<?php
namespace libraries;


/**
 * php 反解析加密url
 *     js 采用escape() 方式加密中文字段
 *     
 * @author Carey
 */
class DecodeUrl
{
    public function __construct()
    {
        
    }
    
    /**
     * UTF8 unescape 解密
     * @param unknown $str
     */
    public static function unEscapeUtf( $str )
    {
        $ret = '';
        $len = strlen($str);
        for ($i = 0; $i < $len; $i++)
        {
            if ($str[$i] == '%' && $str[$i+1] == 'u')
            {
                $val = hexdec(substr($str, $i+2, 4));
                if ($val < 0x7f) $ret .= chr($val);
                else if($val < 0x800) $ret .= chr(0xc0|($val>>6)).chr(0x80|($val&0x3f));
                else $ret .= chr(0xe0|($val>>12)).chr(0x80|(($val>>6)&0x3f)).chr(0x80|($val&0x3f));
                $i += 5;
            }
            else if ($str[$i] == '%')
            {
                $ret .= urldecode(substr($str, $i, 3));
                $i += 2;
            }
            
            else $ret .= $str[$i];
        }
        
        return $ret;
    }
    
    /**
     * GB2312 unescape 解密
     * @param unknown $str
     */
    public static function unEscapeGbk($str) 
    {
        $str = rawurldecode($str);
        preg_match_all("/%u.{4}|&#x.{4};|&#d+;|.+/U",$str,$r);
        $ar = $r[0];
        foreach($ar as $k=>$v) 
        {
            if(substr($v,0,2) == "%u")
                $ar[$k] = iconv("UCS-2","GBK",pack("H4",substr($v,-4)));
            elseif(substr($v,0,3) == "&#x")
                $ar[$k] = iconv("UCS-2","GBK",pack("H4",substr($v,3,-1)));
            elseif(substr($v,0,2) == "&#") 
                $ar[$k] = iconv("UCS-2","GBK",pack("n",substr($v,2,-1)));
            
        }
        
        return join("",$ar);
    }
}

?>